easyPDF.js

function easyPDF(_base64, _title) {
	var re = /(?<=\^PDF\^\^base64\^)(.*)(?<==)/;
	_base64 = re.exec(_base64)[0]
	// HTML definition of dialog elements
	var dialog = '<div id="pdfDialog" title="'+_title+'">'+
            			'<label>Page: </label><label id="pageNum"></label><label> of </label><label id="pageLength"></label>'+
            			'<canvas id="pdfview"></canvas>'+
            		'</div>';
	$('#pdfDialog').iziModal('close')
	$("div[id=pdfDialog]").remove();
	$(document.body).append(dialog);

	// We need the javascript object of the canvas, not the jQuery reference
	var canvas = document.getElementById('pdfview');
  	// Init page count
	var page = 1;
	// Dialog definition
	
	
	
	// TODO: finish converting from popup to iziModal
	
	
	
	
	$( "#pdfDialog" ).iziModal({
	    // Moves controls to top of dialog
		open: function (event, ui) {
			$(this).before($(this).parent().find('.ui-dialog-buttonpane'));
		},
		width: ($(window).width() / 2),
	    modal: false,
	    position: {
	  		my: "top",
	    	at: "top",
	    	of: window,
	    	collision: "none"
	    },
	    buttons: {
	    	"Back": {
	        click: function () {
	        	RenderPDF(-1)
	        },
	        text: 'Previous',
	      },
	      "Next": {
	        click: function () {
	        	RenderPDF(1)
	        },
	        text: 'Next',
	      },
	      "Confirm": {
	        click: function () {
	          $(this).dialog("close");
	          $("#pdfDialog").remove()
	        },
	        text: 'Close',
	      }
	    }
	});

	// Init page number and the document
	$('#pageNum').text(page);
	RenderPDF(0);

	// PDF.js control
	function RenderPDF(pageNumber) {
		var pdfData = atob(_base64);
		pdfjsLib.disableWorker = true;
		
		// Get current global page number, defaults to 1
		displayNum = parseInt($('#pageNum').html())
		pageNumber = parseInt(pageNumber)
		
		var loadingTask = pdfjsLib.getDocument({data: pdfData});
		loadingTask.promise.then(function(pdf) {
			// Gets total page length of pdf
			size = pdf.numPages;
			$('#pageLength').text(size);
			// Handling for changing pages
			if(pageNumber == 1) {
				pageNumber = displayNum + 1;
			}
			if(pageNumber == -1) {
				pageNumber = displayNum - 1;
			}
			if(pageNumber == 0) {
				pageNumber = 1;
			}
			// If the requested page is outside the document bounds
			if(pageNumber > size || pageNumber < 1) {
				throw "bad page number";
			}
			// Changes the cheeky global to our valid new page number
			$('#pageNum').text(pageNumber)
			pdf.getPage(pageNumber).then(function(page) {
				var scale = 2.0;
				var viewport = page.getViewport(scale);
				var context = canvas.getContext('2d');
	  			canvas.height = viewport.height;
	  			canvas.width = viewport.width;
	  			var renderContext = {
	  			  canvasContext: context,
	  			  viewport: viewport
	  			};
			  	page.render(renderContext);
			});
		}).catch(e => {});
	}
}